How fast do user minutes get charged

[usa2k]

I know they thought that the minutes in billing looked more cluttered.
It was because of my initial post in this thread I realized that calls were not affecting the balance.

And I had a couple 2 min calls that had no charge, but the 20 minute call did. All same destination. Ticket ID: MCA-306096

NOW I see the balance has gone down .... but I can't tell how they are being applied?

Usage Charge $3.06 Debit 2010-02-03 21:17:54